Improvement in gang-planks



JOHNSON. Gang-Planks.

Patented April I5, 1873.

luveutnr:

UNITED STATES PATENT OFFICE.

FRANK G. JOHNSON, OFv BROOKLYN, NEW YORK.

`IMPROVEMENT IN GANG-PLANKS.

Specification forming part of Letters Patent No.'l37 ',776, dated April 15, 1873; application filed August 28, 1872.

To all whom it may concern:

Be it known that I, FRANK G. JOHNSON, of. Brooklyn, in the county of Kings and State of New York, have invented a new and useful Method of Constructing Gang Blanks for Steamboats and other Vessels; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable Others skilled in the art to make and use the same, reference being had to the accompanying drawing forming part of this specication.

My invention relates to the method of handling or moving gang-planks, as when they are drawn from the dock to the boat or from the boat to the dock tO afford a passage from the one to the other.

Gang-planks for the passage of horses and vehicles, being necessarily heavy, require the force of from four to twelve men to overcome the friction between them and the dock in hauling them on the dock to and from the boat. The object of my invention, therefore, is to facilitate the handling of gang-planks in such a manner and to such an extent that only a Y relatively small force is required for hauling or moving them on the dock to and from the boa-t.

Figure l represents the ga-ng-plank as seen when looking down from above it. Fig. 2 represents -a side view.

Similar letters of reference indicate corresponding parts.

A represents the floor of an ordinary heavy gang-plank, andl B B its sides.

two simple levers, attached one on each side of the gan g-plank by means of abolt, d, which bolt acts as the'fulcrum of the lever. D is a roller, attached to the short arm of the lever, the lever being placed so as to bring the roller in the center (from end to end) of the gang-plank. F F andE E are hauling-ropes, passingthrough G C represent the eyes or rings H I, and secured to the end of the long arm of the lever O at c.

The operation of my invention is described as follows: By pulling on the hauling-ropes in either direction, as indicated by the arrows, Fig. 2, the long arms of the levers G O are drawn up against the eyes H H, which throw the rollers D D (on the short arms of the levers) down upon the ioor J J of the dock, causing the levers and rollers to take the position shown by the dotted lines Gr g, which (as the floor of the dock cannot move) of course elevates the fulcrum of the levers, and thus lifts the gang u plank a short distance from the floor of the dock, and throws the entire weight of the plank upon the rollers D D. As soon as the hauling-ropes are slackened, of course the gang-plank settles or falls down and rests firmly upon the door of the dock, the same as if it were not provided with rollers at all.

Thus it will be seen that by attaching the ordinary hauling-ropes to the levers O O, and passing them through the eyes H I, the very act of hauling the gan g-plank throws or places it while (and only while) it is being hauled upon casters or rollers, which enables two men to haul a gan g-plank that would require, ordinarily, the force of from four to twelve men tO handle.

Having thus described the construction and operation of my invention, what l claim as new, and desire to secure by Letters Patent,

The combination of the levers C C and hauling-ropes F F and E E with the gangplank A, A

substantially in the manner and for the pur- 

